It is desirous to provide a substantially clear or a lightly tinted flint container glass composition to provide relatively clear transparent flint glass containers that absorb UV light so as to protect the liquid inside such as Champagne or wine.
As to prior art showing Fe.sub.2 O.sub.3 or any amount of MnO in glass composition there are the following documents:
1. Central Glass Co. U.S. Pat. No. 5,362,689. PA1 2. Corning (Morgan) U.S. Pat. No. 5,422,755. PA1 3. Guardian Industries U.S. Pat. No.5,214,008. PA1 4. Ferro (Roberts) U.S. Pat. No. 4,859,637. PA1 5. Chemical Composition of Container Glasses--Sharp (Table 1) 1930's.
Central Glass Co. U.S. Pat. No. 5,362,689 discloses a soda-lime-silica sheet glass composition that contains Fe.sub.2 O.sub.3 (0.1-0.60) and 5-350 ppm MnO. The MnO is used in trace amounts. The ultraviolet absorbing ingredients appear to be CeO.sub.2, TiO.sub.2 and SO.sub.3. In Column 5, lines 55-66, the addition of very small amounts of MnO are discussed and there is disclosed a prohibition against the use of larger amounts of MnO.
Coming (Morgan) U.S. Pat. No. 5,422,755 discloses a soda-potassia-silica glass composition for an ophthalmic lens. There is disclosed the use of V.sub.2 O.sub.5 (1.5-3.5% ) and MnO.sub.2 (1-4%). The
Guardian Industries U.S. Pat. No. 5,214,008 shows a soda-lime silica glass composition for a flat glass. CeO.sub.2 and other UV absorbing ingredients such as TiO.sub.2, MoO.sub.2, V.sub.2 O.sub.5 and Fe.sub.2 O.sub.3 are disclosed, for instance, in Column 2, line 28-50.
Ferro (Roberts) U.S. Pat. No. 4,859,637 shows lead-free glass compositions with a U.V. absorbing material selected from the group consisting of cerium oxide, manganese oxide, iron oxide, cobalt oxide, copper oxide, vanadium oxide and molybdenum oxide. The glass is used with a ceramic pigment to form an ink composition.
The reprint "Chemical Composition of Commercial Glasses". (Sharp) shows in Table 1 some ancient soda-lime-silica glass compositions containing (0.54-0.9), Fe.sub.2 O.sub.3, and low amounts (0.61-0.97) of MnO, apparently present from contamination.